Contraction control joint



July 9, 1968 A. J. HARBERT CONTRACTION CONTROL JOINT Filed y 26, 1966 2Sheets-Sheet 1 I N VEN TOR.

ATTORNEY July 9, 1968 A. J. HARBERT CONTRACTION CONTROL JOINT 2Sheets-Sheet 2 Filed May 26, 1966 INVENTOR.

ARNEY J. HARBERT ATTORNEY 3,391,510 CONTRACTIGN CONTROL JOINT Arney .I.Harbert, 6065 Pierce, Arvada, Colo.

Filed May 26, 1%6, S r. No. 553,198 16 (llaiins. (Q1. 52-396) ABSTRACTOF THE DESCLOSURE This invention relates to novel and improved masonrycontrol joints, and more particularly relates to a contraction controljoint being adaptable for installation vertically between adjacent wallportions of a building in order to establish improved lateral stabilityand more effective load transfer between the wall portions.

A particular problem inherent in the construction of masonry or concretebuilding wall structures is that of cracking, largely due to the absenceof an effective means of transferring loads laterally or in shear acrossthe spaces or parting lines formed by contraction of the wall portions.Although various types of joints and reinforcing members have beendevised in the past to overcome this problem, there is nevertheless adefinite need for a control joint which will more effectively transferloads between building wall portions and in such a way as to greatlyminimize cracking while establishing a weatherproof, watertight sealbetween the wall portions. Moreover it is desirable that the joint bereadily conformable for use either between flat, grooved or recessedconfronting wall surfaces.

It is therefore an object of the present invention to provide for anovel and improved method and means for transferring loads betweenadjacent wall portions of a building wall structure, particularly thosecomposed of masonry or concrete; and in accomplishing same to insurecomplete lateral stability of the wall by effectively transferring windand other loads directly between the adjacent wall portions in anefficient and reliable manner.

Another object of the present invention is to make provision for therequisite lateral stability in a building wall structure composed ofmasonry or concrete whereby to minimize cracking in the walls and toestablish complete weatherproof seal characteristics at the jointnotwithstanding elongation of the joint or shifting of the walls.

A further object of the present invention is to provide for acontraction control joint adaptable for use in virtually any type ofmasonry or concrete building wall structure, such as, poured concrete,precast concrete, concrete block, brick, tile, stone and the like, andwherein the control joint may be furnished in any desired length orwidth, and further may be cut to size in the field according to therequired length and wall thickness; and furthermore wherein the controljoint in accordance with the present invention may be used singly or incombination and is further adaptable for use either between flat,grooved or recessed wall surfaces.

A still further object of the present invention is to minimize lateralslippage between adjacent wall portions of a building structure and toprovide for increased lateral stability by transferring lateral loadsthrough any of four 339L510 Patented July 9, 1968 different possiblecombinations consisting of load transfer between opposing wall surfacesand between opposite sides of the joint.

An additional object of the present invention is to provide acontraction control joint which is economical in construction as well asbeing time and labor-saving in installation and use and further effectssubstantial savings in the cost of sealants required.

In accordance with the present invention, different forms of contractioncontrol joints are hereinafter illustrated and described specificallyfor installation in the space formed as a result of contraction betweenadjacent wall portions of a concrete or masonry structure. In each form,the joint is capable of forming a weatherproof seal across the spacewhile effectively transferring loads particularly in shear between theadjacent wall portions along opposite sides of the space and either fromone side of the wall portion to the other or from one side of the jointto the other. In each form of invention, the control joint preferably isformed of a unitary sheet metal strip which is bent along longitudinallines throughout its length to provide convex sealing edges alongopposite sides of the space and which edges may either be flush with orrecessed within the space. To form a seal along opposite margins of thejoint, the sealant, such as, a caulking compound may be applied alongthe convex edges so that the edges will have the tendency of spreadingthe sealant outwardly into the pores of the masonry or concrete wallstructure to form a waterproof seal. Intermediately between the convexedges, the joint is further bent to provide an intermediate channel orkey-shaped portion extending in a perpendicular direction across thespace between the wall portions, and the channel section is grouted insuch a way that shear loads are carried directly through the grout andchannel portion between the confronting surfaces. In addition, the jointis comprised of alternate angular and transverse bends on opposite sidesof the intermediate channel-shaped portion which will further cooperatein transferring loads in shear between the end surfaces. The entirejoint may be grouted with mortar to cooperate in transferring loads orthe same may be a complished in certain applications by grouting oneside of the joint or simply by grouting through the channel sectiononly. It is emphasized in this connection that the joint is capable oftransferring shear loads in any given direction or angle between groovedor flat confronting end surfaces. By virtue of the symmetricalconfiguration of the control joints to be described, they may befabricated in standard lengths and widths, but may be reduced in lengthor width according to special applications in the field without reducingtheir effectiveness in use. In this relation, the joints may be usedbetween adjacent concrete or masonry wall surfaces as well as betweensteel or concrete columns and masonry or concrete wall surfaces andfurther may be used singly or in combination in relatively thick wallsor in double walls all in a manner to be described.

The above and other objects, advantages and features of the presentinvention will become more readily appreciated and understood from thefollowing description, the accompanying drawings and the appendedclaims.

In the drawing:

FIGURE 1 is a view in elevation of a control joint installed in thevertical space formed between rows of concrete blocks.

FIGURE 2 is a side view of the control joint installed in the verticalspace of a wall structure as shown in FIGURE 1.

FIGURE 3 is an enlarged cross-sectional view of one form of controljoint in accordance with the present invention.

FIGURE 4 is a cross-sectional view of another form of control joint.

FIGURE 5 is an enlarged cross-sectional view of still another form ofcontrol joint.

FIGURE 6 is a cross-sectional view showing the use of a pair of controljoints in combination with a double wall structure.

FIGURE 7 is another cross-sectional view of a single control jointpositioned in the space within a double wall structure; and

FIGURE 8 illustrates the application of still another form of controljoint in a narrow wall structure alongside a column.

Referring in detail to the drawings, FIGURES l to 3 illustrate a controljoint 10 embodied in a building wall structure made of staggered,horizontal rows of concrete blocks generally designated at B. Atselected intervals along the wall structure vertical parting lines leftbetween the walls will permit contraction of the wall portions so as toform vertical spaces P, as represented in FIGURE 1, which extend theentire height of the building wall structure between confronting wallsurfaces of the blocks B. The blocks B along opposite sides of the spacemay have facing end surfaces of different specific configurations wellknown in the art; for example, the blocks may be hollow or solid-coreblocks having flat, unbroken end surfaces or may be suitably notched orrecessed in various ways to be illustrated for use along window sashsections and which blocks are commonly referred to as sash blocks.

Generally, in accordance with the present invention, the joint 10 isformed of an elongated sheet metal strip which is dimensioned to extendthe entire length and to traverse the substantial width of the space P.In each form tobe described, the strip is preformed or prefabricated tobe of uniform cross-section throughout its length and specifically insuch a way as to establish complete lateral stability between the wallportions by transferring shear loads across the space. Moreover, asealant may be applied along opposite lateral margins of the strip, andthe remaining space may be grouted by filling with a mortar or suitableconcrete mix along one or both sides of the strip. As illustrated inFIGURES 1 and 2, notches 11 may be formed in opposite ends of the strip,or apertures 12 may be formed at intervals along the length of the stripto permit insertion of reinforcing bars 13 which are embedded within themortar joints between the concrete block rows B.

Now considering in more detail the form of control joint shown in FIGURE3, a contraction control joint 10 is positioned within the space Pbetween rows of blocks B and B. The blocks B are arranged insuperimposed relation with their facing end surfaces 14 being recessedto provide aligned vertical notches 15. In turn the blocks B have spacedend surfaces 16 separated by an intermediate, relatively broad recessedarea 18 opposite the notch together with relatively shallow recessedareas 19. The joint 10 is formed of an elongated sheet metal stripmember which is bent along longitudinal lines to define return flanges24 along opposite lateral margins of the strip, each flange beingcorrespondingly formed of a succession of three angular portions 25, 26,and 27 with each portion being bent at an acute angle to the nextpreceding portion. Here it will be seen that sections 25 and 26 extendacross the end of the space with opposite corners contacting theconfronting end surfaces of the blocks B and B and specifically topresent an outwardly projecting convex surface between the end surfacesto facilitate application and spreading of a sealant S therealong. Theinwardly directed, terminal portion 27 merely establishes a restrictedspace or cavity 28 Within the flange.

Relatively broad angular portions 30 extend inwardly from each of thereturn flanges 24, and each angular portion 38 is directed at an anglefrom a point contacting the side of the angular portion 25 against theend surface of the block B across the space to the opposite end surfaceof the block B Where it is interrupted by a relatively narrow transverseportion 31. The portion 31 extends perpendicularly across the space withits opposite side in turn being joined to one side of a second angularportion 32 which is directed inwardly therefrom and at an anglesubstantially parallel to that of the first angular portion 30.Together, the innermost angular portions 32 extend inwardly andterminate in a common;

intermediate, U-shaped channel section or key 34 which has transverseportions 35 interconnected in spaced relation by a common, centralconnecting portion 36 extending between sides of the transverse portion35 opposite that of the innermost angular portions 32. It will be seenthat the channel-shaped section 34 defines a trans verse convergentprojection away from the normal plane of the strip and is dimensioned tofit within the aligned notches 15 formed along the end surface of theblocks B.

Preferably, the joint 10 is completed by filling the inner recessed area18 and the channel-shaped section 34 with mortar 38 which is confinedwithin the recessed area by the innermost angular portions 32 bridgingthe gap across opposing end surfaces. customarily, the mortar willexhibit some shrinkage in setting and be bonded to the surface of theblock B along the recessed area 18; however it is not essential that themortar adhere to the metal strip for effective load transfer, and infact the strip may be treated with an agent specifically to preventbonding of the mortar to the sheet metal. In this relation, the somewhatdivergent sides 35 of the section 34 will permit the mortar to shrink orcontract away from the sheet metal strip. Nevertheless, loads appliedeither normally across the joint or in shear at some angle to normal aretransmitted through the grout and channel section which is reinforced bythe angular and transverse bend portions 30-32.

The sheet metal strip is installed by inserting same vertically throughthe space with the intermediate channel 34 aligned with the notches 15.Once installed, a sealant S is applied under pressure along oppositelateral margins of the strip so that, when forced against the outersurfaces of the angular portions 25 and 26, the sealant will spreadoutwardly against the block end surfaces and into the pores of themasonry along the corners of the flange thereby effecting a completeweatherproof and watertight seal. In turn, mortar 38 is used to fill thespace on one side of the joint between the channel portion and recessedarea 18 or may be used on both sides of the joint to completely fill theremaining space after insertion of the strip. In filling the space, itwill be noted that the flanges 24 on opposite lateral margins willprevent outward flow of the mortar 38 or other grouting composition fromthe space. In this relation, the flanges 24 may be flush with the sidesof the blocks or may be recessed inwardly as shown in FIGURE 3.

In FIGURE 4, the vertical parting line or space P is illustrated betweenrows of concrete blocks B, the blocks having confronting end surfaces 14with aligned, vertically extending center notches 15. A modified form ofelongated sheet metal strip 40 is inserted within the space and is bentto comprise return flanges 42 along opposite lateral margins of thestrip, each flange being defined by a generally V-shaped angular sectionmade up of angular bends 45 and 46 which together present a generallyconvex end surface across the end of the space to facilitate applicationof the sealant. In addition, the third angular portion 47 is directedinwardly at an acute angle from one side of the angular portion 46 tomerge with a relatively broad section 48 extending parallel to and inspaced relation between the end surfaces 14 and being interrupted by Vshaped bends 50, the latter including a transverse portion 51 traversingthe space between the end surfaces. The sections 48 continue inwardly toterminate in a generally U- shaped channel section 52 which isdimensioned to fit within one of the notched areas 15. Again the channeland opposite notch are grouted full, as represented at 53, and thetransverse portions 51 serve to retain the mortar within the designatedarea 53. As described with reference to FIGURE 3, a sealant S may beapplied along the flanged sections 42 to establish a seal with the endsurfaces.

In FIGURE 5, a modified form of joint 18 is vertically installed in thespace formed between rows of superimposed blocks B and B of reducedwidth, and wherein the blocks B have aligned notches and blocks B eachhave a recessed area 18 between end surfaces 16. The joint 10 is formedin much the same manner as the joint 10 shown in FIGURE 3, and iscorrespondingly made up of outer return flanges 24' and angular portions38" terminating in a common U-shaped channel section section 34 which isdirected outwardly for insertion within the notched area 15. As shown,the space is grouted between the recess 18 and the channel section 34,and the angular portions serve to retain the grout Within the spacewhile lending additional reinforcement to the channel section for loadtransfer across the space.

In FIGURES 6 and 7, elongated sheet metal strips are formed in a similarmanner but are dimensioned to be of different widths according to wallthickness. Essentially, each strip 68 is bent to provide return flanges61 along opposite lateral margins and which flanges are again formedwith generally V-shaped angular portions 62 and 63 with a transversereturn portion 64 of limited width. One or more angular portions 66extend inwardly from each return flange and are interrupted bytransverse return portions 67 extending in a perpendicular directionbetween the end surfaces of the wall portions. The innermost angularportions 66 terminate in a channel section 68 made up of transversereturn portions 70 and a common connecting portion 71. As in the otherforms, it will be seen that the transverse portions 70 diverge outwardlysomewhat from the connecting portion 71 so that when the space isgrouted within the channel section the grouting composition in settingup will be free to shrink or withdraw away from the channel section.Referring specifically to FIGURE 6, it will be seen that a pair ofjoints 60 and 60 are used in combination in a double wall structurehaving an inner wall comprised of concrete blocks B and an outer wallcomprised of relatively narrow bricks D, the latter having flat endsurfaces 73. The joint 60 is arranged within the space P between theconcrete blocks B and has a pair of angular portions 66 interrupted by atransverse portion 67 flanking opposite sides of the channel section 68;whereas the joint 60 between the bricks D is formed with one angularportion 66 extending inwardly from each flange 61 for connection toopposite sides of a common channel section 68. It will be noted thatthis form of joint is similar to that shown in FIGURE 5 with theexception that the channel section 68 shown extends in the oppositedirection to that of the channel sec tion 58. Moreover, the concreteblocks B generally correspond to the blocks B as shown in FIGURE 3 toprovide a central relatively deep recessed area 18 in each end surface.Even though the channel section 68 does not project into a recessed areain either of the end surfaces, effective keying and load transfer isaccomplished by grouting the space on both sides of the strip 60 with amortar or concrete mix composition 74 which will adhere to the endsurfaces and cooperate with the strip 68 to transfer loads between thewall portions. In this form the grout is retained within the space bythe return flanges 61 which traverse the ends of the space, and in thisway loads are carried by the grout through the channel sec tion as wellas through the combination angular and transverse bends across the widthof the joint.

-The same result is achieved between flat end wall surfaces of the brickmembers D, since again the grout will act to transfer shear loads invirtually any direction or angle across the joint between theconfronting wall surfaces 73. It will be noted in FIGURE 6 that the wallthickness of the brick members D is approximately onehalf that of theblocks B, and if desired, an effective joint may be formed by breaking astrip 60! in half along its length and inserting it into the spaceformed between the brick members. This may be faciilitated byselectively weakening the joint along the center line or longitudinalaxis of the joint 69 so that for such applications the strip may bereadily divided.

In FIGURE 7, a double wall thickness is again illustrated as beingcomprised of an inner wall formed of blocks B and B and an outer wallmade up of bricks D having a common vertical space or parting line P.Here the joint is defined by a single, relatively wide strip 60 whichtraverses the common space formed between the double wall including theintervening space 76 between the inner and outer wall sections. Again,the strip 60" is comprised of return flanges 61 along opposite marginstogether with a succession of angular and transverse bands 66 and 67flanking opposite sides of an intermediate channel section 68. Theentire joint is grouted full with mortar and in this instance it will beseen that the channel section 68 is disposed between flat end surfaces,as opposed to the notched or recessed areas. Nevertheless, effectivekeying is provided by the strip in cooperation with the mortar totransfer loads in shear both through the channel section 68 and theangular transverse bends 66 and 67.

In FIGURE 8, a modified form of joint 80 is shown for use in a space Pformed in a narrow wall section on one side of a column or pipe memberC. The wall section may be suitably comprised of bricks D having flatend surfaces 73 and in turn the joint is defined by an elongated sheetmetal strip having an outer convex rounded return flange 82, an inwardlydirected angular portion 83 and a channel section 84 at the innerterminal end of the strip. The remaining space is grouted as illustratedand a sealant S is applied along the outer convex surface of the flangeportion 82 so as to spread outwardly into sealed relation between thesides of the flange and the confronting end surfaces of the bricks D, asillustrated. Here it is not at all necessary that the joint be providedwith return sealing flanges along both margins since only one marginacross the external face of the blocks will be exposed. As in the otherforms, the channel section or key, as well as the angular portions willserve to transfer loads in shear across the space.

In the different forms of joints herein illustrated and described itwill be evident that each is capable of controlling load transfer underlateral shifting or movement between closely spaced confronting wallportions of a building wall structure. In this relation, effectivekeying to transfer loads across the space between the wall surfaces isachieved whether or not the channel section is aligned within a notch inone of the end wall surfaces. Moreover, the combination of transverseand angular portions between the channel sections and the end flangeswill cooperate in transferring such loads as well as to retain the groutWithin selected areas of the joint. In order to effect the desiredsealing along opposite margins of the joint, the return flanges may haveouter rounded convex edges as shown in FIGURE 8, although it will beevident that the use of angular or V-shaped return flanges asillustrated in FIGURES 3 to 7 will serve to more effectively spread thesealant outwardly into contact with the confronting end surfaces andresult in improved sealing characteristics. In general, the use of asheet metal section provides the necessary characteristics offlexibility and strength and ready conformability for use in variousinstallations where lateral load stability is a prime requisite. In thisrelation, the joint may be employed in various concrete and masonrystructures, and in wall structures can be used in locations where thewall abuts a column, cross wall, pilaster or wall recess. Moreover,where a space occurs between a masonry wall and steel column the jointmay be inserted within the space and spot-welded or otherwisepermanently aflixed to the steel column to effectively transfer loadsbetween the column and wall structure. The strip can be of any length orwidth, can be employed singly or in combination, and can be used with orwithout other reinforcing means.

It will be appreciated from the foregoing that various modifications andchanges may be made in the construction, combination and arrangement ofparts comprising alternate forms of the present invention. For example,the outer return flanges along opposite margins of the strip will serveas effective closures between the wall surfaces, in the absence of asealant. In this relation, the sealant applied to the return flangeexternally of the building, but in most cases would not be required forthe return flange internally of the building. In addition thereinforcing bars 13 shown in FIGURE 1 would have most useful applicationto concrete wall structures, but generally are not used or required inmasonry walls. It is therefore to be understood that other modificationsand changes may be made without departing from the spirit and scope ofthe present invention as defined by the appended claims.

What is claimed is:

1. A control joint adapted for installation in a space between adjacentwall surfaces of a building structure, said joint comprising anelongated metallic strip traversing the substantial length and width ofthe space, said strip having outer flanged portions traversing the sidesof the space between wall surfaces and a longitudinally extending,generally U-shaped, intermediate channel section between said flangedportions, and a grouting material filling at least the space within saidchannel section and adjacent space communicating with the space withinsaid channel section, said grouting material being bonded to the wallsurface bounding the adjacent space whereby to cooperate with saidchannel section for transferring loads in shear between the adjacentwall surfaces.

2. A control joint according to claim 1, said strip having its channelsection dimensioned to fit within a notched portion along one of thewall surfaces, and said grouting material being bonded to the other wallsurface opposite to the notched wall surface.

3. A control joint according to claim 1, said strip being disposedbetween a pair of relatively flat, spaced parallel wall surfaces, saidgrouting material filling the remaining space between the wall surfaceson opposite sides of said channel section, said flanged portionsretaining said grouting material within the space to harden into bondedrelation with the wall surfaces.

4. A control joint according to claim 1, said elongated metallic stripbeing further characterized by including angular portions traversing thespace between the wall surfaces on opposite sides of said channelsection.

5. A control joint according to claim 1, said channel section having acommon, flat connecting portion and transverse portions divergingoutwardly from said connecting portion, said channel section beingdimensioned to fit within a recessed area within one of the wallsurfaces.

6. A control joint according to claim 1, said outer flanged portionseach being in the form of a return flange presenting a convex surface ofV-shaped cross-sectional configuration traversing the sides of the spacebetween the wall surfaces, and a sealant being applied under pressurealong the convex surfaces of said return flanges into sealed relationwith the wall surfaces.

7. In a control joint for disposition in the space formed betweenadjacent Wall surfaces of a building structure, a unitary metal stripbeing dimensioned to traverse the substantial width and length of thespace, and said strip comprising outer return flanges each presenting aconvex edge portion along opposite lateral margins traversing the spacebetween adjacent wall surfaces, a sealant applied externally along eachof said convex edge portions, a longitudinally extending, generallyU-shaped channel section disposed intermediately of said flangedportions, and generally planar portions extending between opposite sidesof said channel section and said outer flanged portions.

8. In a control joint according to claim 7, said planar portionsincluding a series of relatively wide angular sections interconnected bytransverse sections extending inwardly between each of said flangedportions and opposite sides of said channel section.

9. In a control joint according to claim 7, said metal strip havinggenerally planar portions defined by relatively wide sheet metalsections extending in spaced parallel relation to said wall surfacesbetween each of said flanged portions and opposite sides of said channelsection, each of said relatively wide sections being interrupted by atransversely extending portion traversing the space between the wallsurfaces.

10. In a contraction control joint for disposition in a space betweenadjacent wall surfaces in a building structure, an elongated sheet metalstrip being dimensioned to traverse the substantial length and width ofthe space, said strip being bent along longitudinal lines traversing thelength of said strip to define an alternating series of angular portionsand transverse return portions arranged at intervals across the width ofsaid strip and an intermediate, longitudinally extending channel sectionincluding spaced-apart transverse portions and a common, relatively flatconnecting portion therebetween, and a grouting material being insertedat least within said channel section to cooperate with said sheet metalstrip in transferring shear loads between the adjacent building wallsurfaces.

11. In a contraction control joint according to claim 10, said angularportions being relatively wide and each extending at an angle across thespace between adjacent wall surfaces, and said transverse portions beingrelatively narrow and each extending in a perpendicular direction acrossthe space between the adjacent wall surfaces, each of said transversereturn portions being joined along opposite sides to successive angularportions.

12. In a contraction control joint according to claim 10, said channelsection having said spaced-apart transverse portions extending in adirection opposite to that of said series of transverse return portions.

13. In a contraction control joint according to claim 10, said channelsection having its spaced-apart transverse portions extendingtransversely in the same direction as said series of transverse returnportions.

14. A contraction control joint being adapted for use in a building wallstructure having rows of masonry blocks arranged in superimposedrelation with a vertical parting line forming a vertical space theheight of the wall structure between spaced adjacent wall surfaces, atleast one of each of the adjacent wall surfaces including a verticallyextending groove extending for the entire height of the wall structure,said joint comprising an elongated sheet metal strip disposed in thespace to extend for the substantial height of the wall structure andbeing further dimensioned to traverse the substantial width of thespace, said strip being of uniform cross-section throughout its lengthand being bent along longitudinal lines to define angular flanges alongopposite margins, each presenting a convex surface traversing oppositesides of the space between adjacent wall surfaces, a succession ofrelatively wide angular portions extending inwardly from oppositemargins and an alternating succession of relatively narrow transversereturn portions extending perpendicularly across the space between eachpair of angular sections in succession across the width of the strip,and an intermediate, generally U-shaped channel section between a pairof said angular portions and being defined by spaced,

transverse portions interconnected by a straight portion extendingparallel to the adjacent wall surfaces, said channel section beingdimensioned for insertion within the groove formed in one of theadjacent wall surfaces.

15. A contraction control joint according to claim 14, further includinga sealant applied under pressure along the convex surfaces of saidangular flanges for movement into sealed relation between said flangesand adjacent wall surfaces, and a grouting material inserted at leastwithin said channel section to cooperate in transferring shear loadsbetween the adjacent wall surfaces.

16. A contraction control joint according to claim 14, said angularflanges including a pair of angular portions bent to define a generallyV-shaped convex surface portion across each side of the space.

References Cited UNITED STATES PATENTS Older 94-18 Leach 9418 Weil52-412 Robertson 94-18 Williams 52396 X Spaight 52396 Great Britain.

FRANK L. ABBOTT, Primary Examiner.

ALFRED C. PERHAM, Assistant Examiner.

